How to solve the problem of Game keeps getting deleted from steam library

The game is constantly being removed from the vapor library and the entire 21 GB must be re-downloaded.

Steam has been used since the beginning, but the past two league games have disappeared in my library, entered the store page and reinstalled, If you don't know where to buy the cheapest POE Currency the MMOAH website is your best choice. usually detected existing files, sometimes unable to detect existing files, but it will still download the entire game again.

This problem only happened in other games on the road to exile and did not find this problem (I have more than 200 games). It's also completely random (I initially thought it might be related to switching steam accounts on a PC, but it's now random seams to me).

I also don't want to use it alone, I Buy POE Currency on the MMOAH website and it helped me a lot. because I like to track the hours of playing steam achievements (also steam exclusive MTX). This is also a POE exclusive issue, so it's not like steam or my computer has problems?

It usually only happens in one league, but the league has already had 3 full re-downloads, about 10 times disappearing from the account (but being able to rediscover the files).